Results: David Barosso & Anthony Stillman. optical measurements.

OK, folks. I have the results of our last test. (Or, at least, my interpretation of it all.)

It looks like the last 8 hours on the edge (6 hours with the 16" tool and 2 hours of smoothing with the 24" tool in two sessions of 3+1 each) have taken off 1/3 to 1/2 the glass we needed to remove from the edge.

In the minimax sense, that means we have gone from just over 13 wavelengths to somewhat under 9. (The actual numbers are 13.06 to 8.76 for a difference of 4.3 but I don't trust the data well enough to justify all those digits.) About 1/3 the total in this sense.

As the stroke mostly removed glass from the edge, the actual amount of glass removed there appears to be about 10 wavelengths at the 31.5 inch zone which is about 1/2 of the 20 wavelengths that was there on 11/16/96.

Besides the uncertainty that is ALWAYS present in all of my interpretations of these tests, there are a few caveats.

The stroke produced a pronounced zone in the outer 3 inches. While this zone is turned up and not a problem for further polishing, it did mean that we were unable to take readings in this area.

The stroke also produced a barely noticeable zone around 8 inches further in which was mostly taken care of by the smoothing stroke. This suggests we should slightly increase our ratio of smoothing stroke to edge stroke.

The smoothing has also taken a slight amount of the correction out of the center. This suggests we should decrease our amount of smoothing. Another way to look at it is that, while our edge & smoothing stroke is preventing problem zones on the edge, the cost of that is some slight amount of further correction in the center. This should be no problem.

I guess its back to polishing this Saturday (2/22). Let's try to get together around 10 AM as usual. I'll work out the stroke with Anthony & Dave this week but I suspect we're in for a long session.

We're under 10 wavelengths for the first time. Cool. Dan

Dan Zuras

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